delusion

1 a conception or image created by the imagination and having no objective reality <her idea that her new man is a long lost prince is surely just a delusion> Synonyms chimera, conceit, daydream, fantasy, dream, fancy, figment, hallucination, illusion, nonentity, phantasm (also fantasm), pipe dream, unreality, visionRelated Words ignis fatuus, mirage, will-o'-the-wisp; brainchild, idea; concoction, fable, fabrication, fiction, invention; envisaging, imaging, visualization; cloud-cuckoo-land, cloudland, Shangri-la, utopia; daymare, nightmareNear Antonyms actuality, fact, reality

2 a false idea or belief <he appears to suffer from the delusion that he's the best reporter in the business> Synonyms fallacy, error, falsehood, falsity, hallucination, illusion, misbelief, misconception, myth, old wives' tale, untruthRelated Words factoid; superstition; fiction, pretense (or pretence); distortion, inaccuracy, misapprehension, miscomprehension, misinterpretation, misjudgment, misperception, misunderstanding; misinformation, misknowledge, misreport, misrepresentation, misstatement; sophism, sophistry; fib, half-truth, lie, story, taleAntonyms truth, verity